JPH04126815A - Ultra-fine fiber-forming conjugate fiber - Google Patents

Abstract

PURPOSE:To provide the subject fiber having excellent processing stability and comprising a sheath-core conjugate fiber whose sheath portion comprises separable plural portions, the sea portion of whose core portion comprises a solvent-dissolvable polymer and the island portions of whose core portion form ultra-fine fibers. CONSTITUTION:The objective fiber comprises a sheath-core fiber, the sheath portion comprising a plurality of mutually separable portions 2 and 3, the core portion 1 having a sea-island structure, the sea component of the core portion 1 comprising a polymer removable with a solvent, such as PVA, and the island component comprising a polymer such as PE and forming ultra-fine fibers having a single fineness of <=0.1d. The separable portions of the sheathe portion of a woven fabric prepared of the conjugate fibers are separated from each other and the sea portions of the core portions are removed with a solvent to provide the woven fabric containing ultra-fine fibers and having excellent touch.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to microfiber-generated fibers, and more specifically, the present invention relates to microfiber-generated fibers, and more specifically, by removing a part of the constituent components using a solvent or the like, ultrafine fibers can be produced.
It is a composite fiber characterized by having a sea-island structure that generates w&m, and wrapping the sea-island structure with a peelable polymer, and is an ultra-fine fiber with excellent manufacturing stability, processing stability, and storage stability. The present invention relates to fiber-generated conjugate fibers and woven or nonwoven fabrics having ultrafine fibers obtained using the same.

[Conventional technology]

Recently, as clothing becomes more luxurious and diversified, attempts have been made to improve the texture by making the fibers ultra-fine. Furthermore, as the development of applications for synthetic paper, nonwoven fabrics, etc. progresses, there is a desire to develop methods for producing ultrafine fibers. As a fiber that generates ultrafine fibers, ultra-fine fibers, generally called sea-island fibers, are extremely useful, and many new products using them are now on the market.

Among these sea-island type fibers, especially
, No. 8, etc., is a method in which different polymers of a sea component and an island component are blended and melt-spun, and then the sea component is removed with a solvent, leaving only the island component. Further, the material disclosed in Japanese Patent Application Laid-Open No. 60-21904 and the like is a material in which different types of polymers are compositely spun to form an island structure. However, all of these have drawbacks, such as the fact that stable spinning is not possible due to the poor spinnability of the sea component, or that the strength of the ultra-m fiber bundle obtained by removing the sea component is insufficient. .

On the other hand, ultrafine fiber-generated conjugate fibers, which are disclosed in Japanese Patent Application No. 01-18269 filed by the present applicant as an improved version of these sea-island type fibers, are conjugate fibers consisting of an ultrafine fiber-generated portion having a sea-island structure and other portions, The sea-island structure part is exposed on the fiber surface, and the island component is divided into single yarns with a fineness of 0. By using ultrafine fibers with a diameter of 1 denier or less and using fibers with a single fiber fineness of 0.5 denier or more in the other parts, sufficient strength and stable spinnability can be obtained.

However, if a water-soluble polymer such as polyhinyl alcohol is used as the sea component of the sea-island structure in this sea-island type microfiber-generated fiber, an aqueous solution fiber finishing agent cannot be used, and moisture in the air will be absorbed during storage. There were many problems such as fusion of fibers.

[Problem to be solved by the invention]

An object of the present invention is to provide ultrafine fiber-generated fibers that have excellent manufacturing stability, processing stability, and storage stability.

[Means to solve the problem]

In order to solve the above-mentioned problems with the sea-island type microfiber-generated fibers, the present inventor has conducted extensive research and discovered that the surfaces of the microfiber-generated fibers can be peeled from each other and are covered with a polymer having low moisture permeability. This led to the completion of the present invention after realizing that the same results could be obtained.

The ultrafine fiber-generated conjugate fiber of the present invention is a sheath-core type conjugate fiber, and the sheath portion is composed of multiple parts that can be peeled from each other,
The window portion has a sea-island structure, the sea component of this window portion is made of a polymer that can be removed with a solvent, and the island component has a single yarn fineness of 0. 1
It is a composite fiber characterized by forming ultrafine fibers with a denier or less.

The ultrafine fiber bundle of the present invention is a fiber bundle containing ultrafine fibers obtained by peeling off the sheath portion and removing the sea component of the window portion of the above-mentioned ultrafine fiber-generated conjugate fiber.

The woven fabric or nonwoven fabric having ultrafine fibers of the present invention is obtained by peeling off the sheath portion of the ultrafine fiber generated conjugate fiber from the woven fabric or nonwoven fabric produced using the ultrafine fiber generated conjugate fiber, and
A woven or nonwoven fabric containing ultrafine fibers obtained by removing sea components from the window area.

The composite fiber in the present invention may have any form as long as a plurality of removable sheath parts wrap the surface of a window part having a sea-grain structure, but each sheath part has a fineness of 0. 3
It is particularly desirable that the material be at least one denier. Each sheath component is Q
If it is less than 3 denier, the fiber strength or the strength of the woven or nonwoven fabric obtained using this fiber may decrease. As an example of a composite fiber form, a window portion (1) having a sea IJ3 structure and a composite portion (1) constituting a sheath portion are used.
2) and (3) are composite fibers wrapped in a side-by-side type (Fig. 1).

In the present invention, peeling of the sheath portion does not mean that the plurality of parts constituting the sheath portion do not need to be completely divided as shown in FIG.
As shown in the figure, peeling to the extent that the window portion having a sea-island structure is exposed on the surface of the fiber is sufficient.

As the polymers used in the composite part constituting the sheath part of the composite fiber of the present invention, a combination of polymers with relatively poor compatibility among polyolefins, polyamides, polyesters, etc., which are generally used as fiber raw materials, is used. Examples include polypropylene/polyethylene terephthalate, polypropylene/nylon 6, and the like.

For the sea component of the window portion of the composite fiber of the present invention having a five-island structure, a polymer that can be removed with a solvent or the like, such as water-soluble thermoplastic polyvinyl alcohol, can be used.

The polymer used for the island component of the window portion having a sea-island structure of the composite fiber of the present invention may be any polymer as long as it is not dissolved in the sea component and can form an independent island structure. For example, when thermoplastic polyvinyl alcohol is used as the sea component, polyolefins such as polyethylene and polypropylene can be used.

An example of a method for forming a fiber cross section as shown in FIG. 1 is a method using a spinneret or the like as shown in Japanese Patent Application No. 02-172719 filed by the present applicant.

As a method for spinning the window portion into a sea-island shape, a conventionally known method can be used, for example, a method of polymer blending both sea-island components as disclosed in Japanese Patent Publication No. 47-37648.

Hereinafter, this description will be explained in detail with reference to examples.

〔Example〕

Example 1 As a component constituting the window part, thermoplastic polyvinyl alcohol with a sea component (melt flow rate 1, 190°C3
0 g/10 m1n, degree of polymerization 400, degree of saponification 62%) and polypropylene as an island component (melt flow rate 230
'030g/10m1n) at a weight ratio of 1:1, spinning temperature 2300C1 extrusion amount 100g
/min, and polypropylene (melt flow rate 230"C30g/10m1n) as a component constituting a part of the sheath part (2 parts in Figure 1) was spun at a spinning temperature of 2.
Polyethylene terephthalate (intrinsic viscosity 0.65) was spun as a component constituting the other parts (part 3 in Figure 1) at a spinning temperature of 280° C. and an extrusion rate of 50 g/min.
°C1 throughput 50 g/m i, n, diameter 0.
A spinneret with a 6 mm circular spinning hole (200 spinning holes)
1000 while applying an aqueous solution (5wt%) of C and C alkyl phosphate potassium salt (C:C=18 1.2:1).
m / m j, n, undrawn yarn (9d /
f) was obtained.

This undrawn yarn was stretched 3 times while heating to 90° C. to obtain a drawn yarn (3d/f) of ultrafine fiber-generated conjugate fibers. As a result of observing the cross section of the sea-island part of this drawn yarn under a microscope, the number of island components was several hundred to several thousand, and the diameter was 0.01 to 4.
It was μm. Further, this drawn yarn was left in air at a temperature of 25° C. and a humidity of 50% for 30 days, but no fusion of the fibers occurred due to moisture absorption.

The drawn yarn of the resulting microfiber-generated composite fibers was mechanically crimped (1
The web was cut into 51 mm (3 threads/inch) and stabilized, and then carded using a roller card machine to form a web of 14 dimensions and 50 g/m2. This web was processed using a fork needle machine to simultaneously peel off the sheath part and make the web into a non-woven fabric, and then washed with water (30"C) to remove sea components from the window area. This non-woven fabric was observed under a microscope. As a result, many ultrafine polypropylene fibers were generated.

In addition, the sheath was made of polypropylene (approximately 0,
75 d/f) and polyethylene terephthalate (approximately 0.75 d/f) as shown in (2) and (3) in Figure 2.
) was seen in the shape. Table 1 shows the measurement results for the Q-fiber strength and storage stability of this drawn yarn, the strength of the nonwoven fabric, and the fiber diameter of the generated ultrafine fibers.

Example 2 Polyethylene (melt flow rate 190°C) was used instead of polypropylene used as the island component of the window part in Example 1
Nylon 6 (melt flow Spinning rate 275℃ 85g/10m1n) Spinning temperature 25
The same procedure as in Example 1 was carried out except that the extrusion rate was changed to 0°C and the extrusion rate was 50 g/min, and each was supplied to the spinneret.
I got it. As a result of observing the cross section of this drawn yarn with a microscope,
The number of island components is several hundred to several thousand, and the diameter is 0.01 to several thousand.
It was 4 μm. Further, this drawn yarn was left in air at a temperature of 25° C. and a humidity of 50% for 30 days, but no fusion of the fibers occurred due to moisture absorption.

The obtained drawn yarn was made into a nonwoven fabric by the same operation as in Example 1,
After washing with water, observation under a microscope revealed that many ultrafine polyethylene fibers had been generated. In addition, the polypropylene (approximately 0.75 d/f) and nylon 6 (approximately 0.75 d/f) fibers that formed the sheath were shown in Figure 2 (
It was observed in the shapes shown in 2) and (3). Table 1 shows the measurement results for the fiber strength and storage stability of the drawn yarn, the strength of the nonwoven fabric, and the fiber diameter of the generated ultrafine fibers.

Example 3 As the core part, thermoplastic polyvinyl alcohol with sea component (melt flow rate 190°C 50 g / 10 m
in, polymerization degree 400, saponification degree 62%) and polypropylene (melt flow rate 230℃ 3
0g/10mln) at a weight ratio of 1:1, spinning temperature 230℃, extrusion ft 100
g/min, the component that forms part of the N part (
2 parts in Fig. 1), polypropylene (melt flow rate 23 o C 30 g/10 min) was spun at a spinning temperature of 230 C and an extrusion rate of 50 g/min.
Polyethylene terephthalate (intrinsic viscosity 0.65) was used as a component constituting the other parts (part 3 in Figure 1) at a spinning temperature of 280'C1 extrusion 1k 50 g/min.
Then, the yarn was fed to a spinneret (200 spinning holes) having circular spinning holes with a diameter of 0.4 mm, and the take-up speed was 3 o○.
○ Composite spinning using m/min spunbond method,
A fleece with a basis weight of 30 g/m 2 was obtained. The obtained composite fiber had a cross section as shown in FIG. This fleece was left in air at a temperature of 25°C and a humidity of 50% for 30 days, but no fusion of fibers occurred due to moisture absorption.

The obtained fleece was subjected to water needle processing (water pressure 70
Kg/cm), the sheath part was peeled off, the sea component of the core part was removed because it had a sea-island structure, and the fleece was made into a non-woven fabric at the same time. When this nonwoven fabric was observed under a microscope, it was found that many ultrafine polypropylene fibers were generated. In addition, the polypropylene that formed the sheath component (approximately 0.75 d/f
) and polyethylene terephthalate (approximately 0.75d/
The fibers in f) were seen in shapes like (2) and (3) in Figure 2. Table 1 shows the measurement results for the storage stability of this fleece, the strength of the nonwoven fabric, and the fiber diameter of the generated ultrafine fibers.

Example 4 The spinning temperature and extrusion amount of the polymer supplied to the spinneret used in Example 1 were changed, respectively.
At an extrusion rate of 160 g/min, the polypropylene sheath was spun at a spinning temperature of 230°C and extruded at 120 g/min.
The same operation as in Example 1 was carried out except that the polyethylene terephthalate in the sheath was changed to a spinning temperature of 280°C and an extrusion rate of 20 g/min, and a drawn yarn (3d/f) of ultrafine fiber-generated conjugate fibers was prepared. I got it. When the cross section of this drawn yarn was observed under a microscope, the number of island components was several hundred to several thousand, and the diameter was 0.01 to 4 μm. Further, this drawn yarn was left in air at a temperature of 25° C. and a humidity of 50% for 30 days, but no fusion of the fibers occurred due to moisture absorption.

The obtained drawn yarn was made into a nonwoven fabric by the same operation as in Example 1,
After washing with water, inspection using an R machine gun revealed that many ultrafine polypropylene fibers had been generated. In addition, the polypropylene (approximately 0°3 d/f) and polyethylene terephthalate (approximately 0,3 d/f) fibers that formed the sheath component had shapes as shown in (2) and (3) in Figure 2. It was seen.

Table 1 shows the measurement results for the fiber strength and storage stability of the drawn yarn, the strength of the nonwoven fabric, and the fiber diameter of the generated ultrafine fibers.

Example 5 The drawn yarn of the ultrafine fiber-generated conjugate fiber obtained in Example 1 was mechanically crimped (13 threads/inch), cut into 51 mm lengths, and stapled.
A sheath-core type heat-adhesive composite fiber staple (2 denier, 51 mm) whose core component is polypropylene in a weight ratio of 1:1.
It was mixed with cotton. After carding with this roller card machine to obtain a web with a basis weight of 50 g/m2, it was processed with a fork needle machine to peel off the sheath portion of the composite fibers generated from ultrafine fibers. This was further processed with an embossing roll heated to 130°C to make a nonwoven fabric, and then water (3
(0°C) to remove sea components from the core. When this nonwoven fabric was observed under a microscope, it was found that many ultrafine polypropylene fibers were generated. In addition, the polypropylene (approximately 0°75 d/f) and hypholyethylene terephthalate (approximately 0.75 d/f) fibers that formed the sheath component can be seen in the shapes shown in (2) and (3) in Figure 2. These fibers were bonded together using thermal adhesive fibers. Table 1 shows the measurement results for the fiber strength and storage stability of the drawn yarn, the strength of the nonwoven fabric, and the fiber diameter of the generated ultrafine fibers.

Comparative Example 1 Thermoplastic polyvinyl alcohol (Melt Flowray-1-1900C 50 g/10 m i
n, degree of polymerization 400, degree of saponification 62%) and polypropylene (melt flow rate 230°C 30g/10m1n
) were blended at a weight ratio of 1=1, the spinning temperature was 230°C, the extrusion rate was 200 g/min, and the undrawn yarn ( 9d/f) was obtained.

This undrawn yarn was stretched 3 times while heating to 90'C to obtain a drawn yarn (3d/f) of microfiber-generated fibers. As a result of observing the cross section of the sea-island part of this drawn yarn under a microscope, the number of island components was several hundred to several thousand, and the diameter was 0.01 to 4.
It was μm. In addition, this drawn yarn was heated at a temperature of 25°C and a humidity of 5°C.
When it was left in 0% air for 30 days, the fibers fused together due to moisture absorption. Table 1 shows the measurement results for the fiber strength of this fiber and the diameter of the island component in the cross section of the fiber.

Comparative Example 2 The spinning temperature and extrusion amount of the polymer supplied to the spinneret used in Example 1 were respectively changed, and the spinning temperature of the core portion of the mixture of thermoplastic polyvinyl alcohol and polypropylene was 230°C.
One extrusion rate was 170g/min, the polypropylene sheath was spun at a spinning temperature of 23oC, and the extrusion rate was 15g/min.
The polyethylene terephthalate sheath was spun at a temperature of 2.
The operation was carried out in the same manner as in Example 1 except that the temperature was changed to 8° C. and the extrusion rate was changed to 15 g/min to obtain a drawn yarn (3 d/f) of ultrafine fiber-generated conjugate fibers. When the cross section of this drawn yarn was observed under a microscope, the number of island components was several hundred to several thousand, and the diameter was 0.01 to 4 μm. Further, this drawn yarn was left in air at a temperature of 25° C. and a temperature of 50% for 30 days, but no fusion of the fibers occurred due to moisture absorption.

The obtained drawn yarn was made into a nonwoven fabric by the same operation as in Example 1,
After washing with water, observation under a microscope revealed that many ultrafine polypropylene fibers had been generated. In addition, the polypropylene (approximately 0°2 d/f) and polyethylene terephthalate (approximately 0,2 d/f) fibers that formed the sheath component had shapes as shown in (2) and (3) in Figure 2. It was seen.

Table 1 shows the measurement results for the fiber strength and storage stability of the drawn yarn, the strength of the nonwoven fabric, and the fiber diameter of the generated ultrafine fibers.

〔Effect of the invention〕

The ultrafine fiber-generated conjugate fiber of the present invention has 0. A window portion having a sea-island structure that generates ultrafine fibers of 1 denier or less;
Since there is a peelable sheath that wraps around the window, there is no need to make the manufacturing and processing processes non-aqueous even if water-soluble polyvinyl alcohol is used as the sea component of the window with a sea-island structure. Compared to manufacturing only the sea-island structure part that generates ultrafine fibers, operability has been greatly improved. Furthermore, since the sheath part acts as a reinforcing material for the fiber itself and the woven or nonwoven fabric containing ultrafine fibers, it exhibited sufficient strength for practical use. Furthermore, even when storing the ultrafine fiber-generated conjugate fibers, an excellent effect was obtained in that there was no need to adjust the humidity in the air.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a cross section of a composite fiber produced from ultrafine fibers. FIG. 2 and FIG. 3 are diagrams showing the peeling state of the sheath portion of the ultrafine fiber-generated conjugate fiber. 1: Window portion with sea-island structure 2: One component of the sheath portion 3: Other component of the sheath portion U・X Up −8ε

Claims (4)

[Claims] (1) A sheath-core type composite fiber, in which the sheath portion consists of a plurality of mutually peelable parts, the core portion has a sea-island structure, and the sea component of this core portion is made of a polymer that can be removed with a solvent; An ultrafine fiber-generated conjugate fiber characterized in that the island component forms ultrafine fibers with a single filament fineness of 0.1 denier or less. (2) A fiber bundle containing ultrafine fibers obtained by peeling off the sheath portion and removing the sea component of the core portion of the ultrafine fiber-generated conjugate fiber of claim (1). (3) A woven or nonwoven fabric produced using the ultrafine fiber-generated conjugate fiber of claim (1), which is obtained by peeling off the sheath portion of the ultrafine fiber-generated conjugate fiber and removing the sea component of the core portion.
Woven or non-woven fabrics containing ultrafine fibers. (4) From the woven fabric or nonwoven fabric produced using the ultrafine fiber generated conjugate fiber of claim (1) and the thermoadhesive conjugate fiber, the sheath portion of the ultrafine fiber generated conjugate fiber is peeled off, and the sea component of the core portion is removed. Woven or nonwoven fabric containing ultrafine fibers obtained by removing.